Virtual interchangeable storage device

ABSTRACT

Disclosed is a method and apparatus for a storage system comprising at least one mobile random access storage device capable of storing first or second data. At least one docking station is associated with an address wherein the address is identifiable by at least one host computer. A first and second sub-address is associated with the at least one docking station wherein the first and second sub-addresses are identifiable by the at least one host computer. The first sub-address corresponds to a first virtual device adapted for storing the first data on a first virtual media. The second sub-address corresponds to a second virtual device adapted for storing the second data on a second virtual media wherein the second virtual media is a different media type from the first virtual media. The at least one docking station is adapted to be responsive to the at least one host computer as available for storing the first data at the first sub-address or the second data at the second sub-address when the at least one docking station is operatively linked with the at least one mobile random access storage device.

CROSS-REFERENCE TO RELATED APPLICATIONS

None.

FIELD OF THE INVENTION

The present invention relates generally to virtually changing a mobilerandom access storage device to an alternative storage device capable ofstoring received data intended for the alternative storage device.

BACKGROUND

Tape libraries have historically been the primary storage devices foramassed digital data. This has been due in part because of the tapelibraries' ability to store considerably large amounts of data in acost-efficient and data-stable manner. Other types of storage systemscontaining alternative media such as disc drives, optical storagesystems and flash memory, however, are gaining momentum as a consequenceof advancements and relative cost improvements in random access storagetechnology. These alternative storage systems take advantage of randomaccess memory storage functionality which can dramatically speed up datatransfer between a host and storage system.

Generally, a host computer is adapted to store, retrieve, and manipulatedata with specific types of storage systems comprising specific types ofstorage devices operable to manage data on specific types of storagemedia. Such storage operations are typically accomplished by using aspecific data storage protocol compatible with a specific type ofstorage system. For example, if a host computer is adapted to store datain a tape library, communication and data transfer between the tapelibrary and the host is typically accomplished by a tape libraryprotocol. Some storage systems leveraging disc drive storage technologyare configured to emulate a tape library and store data received fromthe host as if they were a tape library using the tape library protocol.Such advances are evident in a Virtual Tape Library (VTL) which is aleading alternative to the traditional tape library.

Though systems like VTLs have virtues such as improved data transferspeed and redundant storage backup using RAID, they are often limited toa fixed storage capacity, unlike the tape libraries which can use amobile, restorable supply of tape cassettes. In addition, storagesystems, such as the VTL, are further restricted to a specific datastorage protocols for storing data.

In an effort to provide an improvement in versatility for storing andretrieving data with a host computer coupled with replenishable storagecapacity, both methods and apparatus are proposed herein. It is toinnovations related to this subject matter that the claimed invention isgenerally directed.

SUMMARY OF THE INVENTION

The present invention relates generally to virtually changing a mobilerandom access storage device to an alternative storage device andovercomes the disadvantages and limitations of the prior art byproviding a method and apparatus for receiving and storing data intendedfor the alternative storage device.

Embodiment of the present invention can therefore comprise a storagesystem comprising: at least one mobile random access storage devicecapable of storing first and second data; at least one docking stationassociated with an address that is identifiable by at least one consumerof data; a first sub-address and a second sub-address associated withthe at least one docking station that are each identifiable by the atleast one consumer of data; the first sub-address corresponding to afirst virtual device adapted for storing the first data on a firstvirtual media; the second sub-address corresponding to a second virtualdevice adapted for storing the second data on a second virtual mediawherein the second virtual media is a different media type from thefirst virtual media; and the at least one docking station adapted to beresponsive to the at least one consumer of data as being available forstoring the first data at the first sub-address or the second data atthe second sub-address when the at least one docking station isoperatively linked with the at least one mobile random access storagedevice.

Another embodiment of the present invention can therefore comprise amethod for saving information in a storage system comprising: receivingan inquiry from a first consumer of data; providing a first addressassociated with a first docking station; providing a first sub-addresscorresponding to a first virtual device adapted for storing first dataon a first virtual media and a second sub-address corresponding to asecond virtual device adapted for storing second data on a secondvirtual media wherein the second virtual media is a different media typethan the first virtual media and wherein the first and secondsub-addresses are associated with the first address; operatively linkinga first mobile random access storage device with the first dockingstation; designating the first mobile random access storage device asthe first virtual device; responding to the first consumer of data thatthe first virtual device at the first sub-address is available forstoring first data; storing the first data received from the firstconsumer of data at the first sub-address on the first mobile randomaccess storage device.

Yet another embodiment of the present invention can therefore comprise asystem for saving information in a storage library comprising: means forreceiving an inquiry from a first consumer of data; means for providinga first address associated with a first docking station; means forproviding a first sub-address corresponding to a first virtual deviceadapted for storing first data on a first virtual media and a secondsub-address corresponding to a second virtual device adapted for storingsecond data on a second virtual media wherein the second virtual mediais a different media type than the first virtual media and wherein thefirst and second sub-addresses are associated with the first address;means for operatively linking a first mobile random access storagedevice with the first docking station for operability; means fordesignating the first mobile random access storage device as the firstvirtual device; means for responding to the first consumer of data thatthe first virtual device at the first sub-address is available forstoring first data; means for storing the first data received from thefirst consumer of data at the first sub-address on the first mobilerandom access storage device.

Yet another embodiment of the present invention can therefore comprise astorage system comprising: at least one mobile random access storagedevice capable of storing data; at least one docking station adapted toreceive and transmit the data; the at least one mobile random accessstorage device adapted to be designated to function as a first or asecond virtual of storage device wherein the second virtual storagedevice is a different type of device from the first virtual storagedevice; the mobile random access storage device capable of storing thedata intended for storage on the first virtual storage device when theat least one mobile random access storage device is designated as thefirst virtual storage device and the at least one mobile random accessstorage device is operatively linked with the at least one dockingstation.

Yet another embodiment of the present invention can therefore comprise astorage system comprising: at least one mobile random access storagedevice capable of storing sequential data and random data; at least onedocking station; the at least one docking station associated with anaddress wherein the address is identifiable by at least one consumer ofdata; a first and second sub-address associated with the docking stationwherein the first and second sub-addresses are identifiable by the atleast one consumer of data; the first sub-address corresponding to avirtual sequential storage device adapted for storing the sequentialdata on a virtual sequential storage media; the second sub-addresscorresponding to a virtual random storage device adapted for storing therandom data on a virtual random storage media; and the at least onedocking station adapted to be responsive to the at least one consumer ofdata as available for storing the sequential data at the firstsub-address or the random data at the second sub-address when the atleast one docking station is operatively linked with the at least onemobile random access storage device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a data storage arrangement constructed inaccordance with an embodiment of the present invention.

FIG. 2 shows an example of a storage system wherein the presentinvention can be practiced in accordance with some embodiments of thepresent invention.

FIG. 3 shows an illustration of an embodiment of an RXT disc drivemagazine and docking station wherein the present invention can bepracticed in accordance with some embodiments of the present invention.

FIGS. 4A and 4B are block diagrams showing virtual storage devices withrespective virtual media associated with a docking station consistentwith some embodiments of the present invention.

FIGS. 5A and 5B are block diagrams illustrating a host computercommunicating with a storage system consistent with an embodiment of thepresent invention.

FIG. 6 is an alternative embodiment showing two docking stationsreceiving and responding to storage operations from a host computer atsubstantially the same time consistent with an embodiment of the presentinvention.

FIG. 7 is an alternative embodiment of the present inventionillustrating docking station responsiveness based on available storagespace consistent with an embodiment of the present invention.

FIG. 8 shows two different host computers performing storage operationswith a storage system at substantially the same time consistent withsome embodiments of the present invention.

FIG. 9 shows a method to practice an embodiment of the presentinvention.

FIG. 10 shows an alternative method consistent with some embodiments ofthe present invention which includes a method step from FIG. 9.

FIG. 11 shows an alternative method consistent with some embodiments ofthe present invention which includes some method steps from FIG. 10.

FIGS. 12A and 12B are block diagrams illustrating embodiments whereinthe present invention can be commercially practiced.

DETAILED DESCRIPTION

Referring to the drawings in general, and more specifically to FIG. 1,shown therein is a block diagram of a data storage arrangement 100constructed in accordance with an embodiment of the present invention.In what follows, similar or identical structure is identified usingidentical callouts.

The data storage arrangement 100 is a block diagram of a host computer102 in communication 104 with a storage system 106. A host computer 102is one embodiment of a consumer of data; other embodiments can alsoinclude another storage system 106 or a streaming output device such asa video server, just to name several examples. A consumer of data is anentity, or entities, that is capable of “taking in” data, for example ahost computer 102 is a consumer when receiving data and a storage system106 is a consumer when receiving data. As one skilled in the willappreciate, in addition to “taking in” data, a consumer of data is alsogenerally capable of transmitting data. The host computer 102 can be apersonal computer, a main frame computer, a server, or any computersystem capable of communication with the storage system 106, just toname a few examples. The communication path 104, at a minimum, needsonly to facilitate communication between the host computer 102 and thestorage system 106. The means for communication can be accomplished by adedicated pathway (such as a SCSI [Small Computer Systems Interface]cabled connection) or, in an alternative embodiment, a pathway over anetwork (such as a LAN, WAN, or other communication architecture), forexample. Furthermore, the communication path can be in the form of awire line pathway, wireless, or a combination thereof, for example.

The storage system 106 is capable of storing and retrieving data for thehost 102 by means of using at least one docking station, such as dockingstation A 108, docking station B 110 and docking station C 112. Dockingstations A 108 and C 112 are each operatively linked with a mobileRandom Access Memory (RAM) device 114, wherein the mobile RAM devices114 are adapted to store data received from the host computer 102 viathe docking stations. A RAM device is capable of storing random data,that is data that is not constrained by a linear format such as tape forexample. In one embodiment, a mobile RAM device 114 can be inserted inthe docking station, such as docking station A 108; however the MobileRAM device 114 need only be operatively linked to a docking station tostore data received via the docking station. Docking station B 110 isnot operatively linked with a mobile RAM device 114 and hence is unableto store data received beyond any storage capacity docking station B 110may comprise, such as Dynamic RAM for example. For purposes ofillustration, communication with the storage system 106 is consideredcommunication with the storage system 106 generally and/or communicationdirectly with components that comprise the storage system 106. A dockingstation, such as docking station A 108, is an apparatus that is capableof coupling with a mobile RAM device, such as mobile RAM device 1114,for storage operations. Several examples of a docking station include aUSB port capable of receiving a USB device, a PCMCIA slot for receivinga PC-card, a disc drive or disc drive magazine receptacle, serial portconnection, parallel port connection, or any other such apparatuscapable of transmitting and receiving data to a storage device via wireline or wireless just to name several examples.

FIG. 2 shows an example of a storage system 106 in accordance with oneembodiment of present invention. Here, an RXT Bank of Drives disc drivemagazine library 200 from Spectra Logic Corp. of Boulder, Colo.comprises a plurality of random access memory devices (in this exampledisc drive magazines 201) and docking stations 202 operatively linked toone another to function as the RXT library 200. The disc drive magazines201 are adapted for mobility, and can be removed from or inserted into adocking station 202, as illustrated by a vacant docking station 204capable of receiving a disc drive magazine 201, for example. The RXTlibrary 200 is capable of communicating with a host, such as the host102, via a sequential storage protocol, such as a tape library protocolused for streaming data to store on tape medium for example.

FIG. 3 shows a more detailed illustration of an embodiment of an RXTdisc drive magazine 201 and docking station 202. Here, a plurality ofdisc drives 308 are shown substantially contained by an enclosure 304generally comprising the mobile disc drive magazine 201. A conventionalmagnetic disc drive 308 is only one embodiment of a RAM device accordingto the present invention, which, in further embodiments, can includeflash memory or optical memory, just to name a few (see below). Theillustrative mobile disc drive magazine 201 is adapted to be received byan opening 306 in the docking station 202 as shown by the arrow 310.While the docking station 202 is shown as one of a number of stations inthe library 200, one of ordinary skill will appreciate that the dockingstation 202, by itself, could be used as a stand-alone storage system.The engaging surface 314 of the mobile disc drive magazine 201 isadapted with electrical contacts (not shown) to contact withcomplementary electrical contacts (not shown) on the engaging surface(not shown) of the docking station 202. When contact is made, the RXTdisc drive magazine 201 is considered operatively linked with thedocking station 202 whereby the transmission of data can occur betweenthe docking station 202 and the mobile disc drive magazine 201.Furthermore, power can be optionally provided to the mobile disc drivemagazine 201 by the docking station 202. Power and data transmissionprovide a cooperatively linked state between the mobile disc drivemagazine 201 and the docking station 202. The docking station 202 iscapable of being communicatively connected with a host computer, such asthe host computer 102, or other storage device/s, such as the RXTstorage library 200 for example, by a coupling means, such as wires,plugs-in, wireless transmission (e.g., IR, RF) or any combination orequivalence thereof. By linking the docking station 202 with the storagesystem 200, a connected disc drive magazine 201 is effectively in acooperatively linked state with the storage system 200.

While the claimed invention has utility in any number of differentapplications, the RXT disc drive magazine library 200 has been providedto illustrate a suitable environment in which the claimed invention canbe practiced. Here, the disc drive magazine 201 is an embodiment of aRAM device, such as RAM device 114. Other RAM devices can include aCompact Disc Read Only Memory (CDROM) for use with a Compact Disc (CD)or other optical storage media, magneto optical systems, disc drive,disc drive magazine comprising multiple disc drives, flash memorydevices (such as a compact flash), floppy disc drive systems, and RAMsemiconductor memory (i.e., an SDRAM, for example).

FIGS. 4A and 4B are block diagrams showing virtual storage devices withrespective virtual media 412 associated with a docking station 408consistent with an embodiment of the present invention. Referring toFIG. 4A, a storage system 400 comprises docking station [1] 408 whereindocking station [1] 408 is associated with address [1] 409. Dockingstation [1] 408 further comprises three sub-addresses, shown herein as[0] 403, [1] 411 and [2] 407. Herein, the convention used to showaddress and sub-address is illustrated by the address:sub-address blocks1:0 402, 1:1 404 and 1:2 406. In one commercial embodiment, thesub-addresses [0] 403, [1] 411 and [2] 407 can be Logical Unit Numbers(LUNs). Both the address [1] 409 and sub-addresses [0] 403, [1] 411 and[2] 407 are capable of being identified by a host computer, such as thehost computer 102 of FIG. 1. As shown here, docking station [1] 408 isoperatively linked with a mobile RAM device 410. The mobile RAM device410 is designated as a device corresponding to sub-address [1] 411.Hence, address:sub-address 1:1 404 corresponds to the docking stationaddress [1] 409 and the mobile RAM device designated sub-address [1]411. Designating the mobile RAM device 410 to a specific virtual storagedevice can be accomplished by a switch system which could, for example,include a manual switch, an RF driven switch, a programmable switch, anauto switch activated by communication with a host computer, or a timebased switch (such that during daytime the mobile RAM device 410 is onevirtual device and at nighttime the mobile RAM device 410 is analternative virtual device), just to name a few examples. In someembodiments, the switch system could be disposed on or in the mobile RAMdevice 410. In an alternative embodiment, the mobile RAM device 410could auto switch to a particular virtual storage device activated bycommunication with a host computer, such as host computer 102 (i.e., themobile RAM device 410 can configure itself as device [1] 411, forexample, if an inquiry by a host computer requiring storage on a device[1] 411 is received by the cooperating docking station 408).

FIG. 4B shows a virtual docking station 412 representing the dockingstation 408 at address [1] 409 consistent with embodiments of thepresent invention. The three address:sub-address blocks 1:0 402, 1:1 404and 1:2 406, and more specifically the sub-addresses [0] 403, [1] 411and [2] 407, correspond to three virtual storage devices capable ofstoring data on three respective virtual storage medium types. As can beappreciated by a skilled artisan, two of the three virtual devices canbe substantially identical virtual devices. In this example, sub-address[0] 403 from block 1:0 402 corresponds to a virtual disc drive system414, sub-address [1] 411 from block 1:1 404 corresponds to a virtualtape drive system 416 and sub-address [2] 407 from block 1:2 406corresponds to a virtual optical disc system 418 capable of cooperatingwith at least one virtual removable optical disc for storage operations.Furthermore, because the operatively linked mobile RAM device 410 isdesignated to correspond to sub-address [1] 411, docking station [1] 408is adapted to be responsive to a host computer, such as host computer102, as available for storage operations as a tape drive system 416.(The virtual disc drive system 414 and the virtual optical disc system418 are unavailable for storage operations in this example.) A mobileRAM device, such as mobile RAM device 410, is capable of emulating aspecific device for use with a media in the virtual sense. For examplethe virtual disc drive system 414 is adapted to store data received asrandom data in a random data protocol, the virtual tape drive system 416is adapted to store data received as sequential data in a sequentialdata protocol, and the virtual optical disc system 418 is adapted tostore data received as random data in a random data protocol and format.In one embodiment, a mobile RAM device can simply function as the mobileRAM device 410. Hence, a virtual device and virtual media can includethe actual mobile RAM storage device 410 as the device capable ofstoring data on a media.

FIGS. 5A and 5B are block diagrams illustrating a host computer 502communicating 504 with a storage system 500 consistent with anembodiment of the present invention. FIG. 5A shows the storage system500 comprising three docking stations, docking station [1] 408, dockingstation [2] 522 and docking station [3] 524. Docking station [1] 408comprises three sub-addresses [0] 403, [1] 411 and [2] 407, dockingstation [2] 522 comprises three sub-addresses [0] 562, [1] 564 and [2]566 shown and docking station [3] 524 comprises three sub-addresses [0]568, [1] 570 and [2] 572. Docking station [1] 408 is operatively linkedwith a mobile RAM device 508 designated as device [0] 403 correspondingto address:sub-address 1:0 402. The host computer 502 is adapted tostore data on a device [0] 403 and hence is engaged with docking station[1] via the address 1:0 402 for storage operations.

FIG. 5A can be used to illustrate one embodiment of the presentinvention whereby the host computer 502 is adapted to manage data at astorage system 500 in a protocol used with a storage device type [0].Following a convention similar to that used in FIG. 4B, the device forsub-address [0] 403 is a virtual disc drive 414, sub-address [1] 411 isa virtual tape drive 416 and sub-address [2] 407 is a virtual opticaldisc system 418. In this embodiment, the mobile RAM device 508 isdesignated as a virtual disc drive 414 (which as previously describedcould be a real disc drive) operatively linked with docking station [1]408. The host computer 502 can transmit a Small Computer SystemsInterface (SCSI) inquiry to scan the storage system's bus (not shown) todiscover what devices comprise the storage system 500. An inquiry can bea host 502 or a user effectively asking the storage system 500 “who areyou?” and “what are you?” The storage system 500 can show that there arethree devices at address [1] 409, corresponding to docking station [1]408; a disc drive 414 at address:sub-address 1:0 402, a tape drivesystem 416 at address:sub-address 1:1 404 and an optical drive system418 at address:sub-address 1:2 406. The storage system 500 is alsocapable of showing that address 1:0 402 is available for storageoperations and addresses 1:1 404 and 1:2 406 are not available forstorage operations. In some commercial applications, this can beaccomplished by transmitting a SCSI ID:LUN (corresponding toaddress:sub-address) response to the host 502 in 16 bytes ofinformation. Further, the devices corresponding to theaddress:sub-addresses 2:0 510, 2:1 512, 2:2 514, 3:0 516, 3:1 518 and3:2 520 of docking stations [2] 522 and [3] 524 respectively will allregister as unavailable to the host computer 502 because there are nomobile RAM devices 114 operatively linked with the docking stations [2]522 and [3] 524. The host computer 502 (adapted to store data on a discdrive for example) determining that a disc drive at address 1:0 402 isavailable for storage can commence storage operations 504 with dockingstation [1] 408 and the mobile RAM device 508.

FIG. 5B shows an alternate embodiment of the present invention of thehost computer 502 performing storage operations via docking station [3]524. In this embodiment a first mobile RAM device 540 is operativelylinked with docking station [1] 408 of the storage system 500 and asecond mobile RAM device 550 is operatively linked with docking station[3] 524 of the storage system 500. The host computer 502 is adapted toperform storage operations with a device type [0]. Through inquiries,the host computer 502 can discover that address:sub-address 1:2 ofdocking station [1] 408, is available for data storage on a device type[2] because mobile RAM device 540 is designated to be a device type [2]407. The host computer 502 can further discover that all of theaddresses associated with docking station [2] 522 are unavailable(because there is no operatively linked mobile RAM device and hence norecording medium for docking station [2] 522 to perform mass storageoperations). Docking station [3] 524 is operatively linked with thesecond mobile RAM device 550 configured with the designation of device[0] 568. The host computer 502, adapted to store data on a device type[0], is engaged in storage operations 504 with docking station [3] 524because the associated address:sub-address 3:0 516 can be positivelyidentified as available for storage operations as a device and mediatype [0].

As is understood by one skilled in the art, a host computer, such as thehost computer 502, generally communicates and stores data in protocolthat may be different for alternative devices and media. For example, atape library protocol includes both a streaming protocol to store datain a linear fashion tailored for tape medium and a media changerprotocol adapted to load tape cassettes in tape drives. In the event adocking station, such as docking station [1] 408, positively indicatesavailability for data storage at a tape drive, such as ataddress:sub-address 1:1 404 for example, the docking station may beadapted to be responsive to instructions as if it were a tape libraryready for data storage.

In one embodiment of the present invention, a library could beconfigured to support both docking stations, such as docking station [3]524, for use with a mobile RAM device, such as the second mobile RAMdevice 550, and at least one tape drive adapted to store data on tapecassettes. An example of such a hybrid library supporting storage onboth real tape cassettes and virtual tape cassettes is the Spectra LogicT950 library.

FIG. 6 is yet another alternative embodiment showing two dockingstations receiving and responding to storage operations from a hostcomputer 502 at substantially the same time. Docking station [1] 408 isoperatively linked with a first mobile RAM device 602 and dockingstation [2] 522 is operatively linked with a second mobile RAM device604. Both the first 602 and second 604 mobile RAM devices are designatedto be device type [0] 506. Both docking stations [1] 408 and [2] 522 areresponsive to the host computer 502 as being available to receive datafor storing at address:sub-address 1:0 402 and address:sub-address 2:0510 both as storage device type [0] able to store data on media type[0]. The host computer 502, adapted to manage data on device type [0],is shown here performing storage operations 620 and 630 via both dockingstation [1] 408 and docking station [2], respectively. Docking station[3] 524 does not have a cooperating mobile RAM device 114 and henceregisters as unavailable for storage operations.

FIG. 7 is an alternative embodiment of the present inventionillustrating docking station responsiveness based on available storagespace. Herein, docking station [1] 408 is operatively linked with afirst mobile RAM device 704 and docking station [2] 522 is operativelylinked with a second mobile RAM device 706. Both the first 704 andsecond 704 mobile RAM devices are designated to be device type [0] 506.In this embodiment, the host computer 702 requires storage of 15 GB ofdata on a device type [0]. Docking station [1] 408 is identified as onlycapable of receiving 150 MB of data for storage on device type [0] ataddress:sub-address 1:0 402. Docking station [2] 522 is identified ascapable of receiving up to 600 GB of data for storage on device type [0]506 at address:sub-address 2:0 510. Hence, the host computer 702 engagesin storage operations via docking station [2] 522 at address 2:0 510.

FIG. 8 shows two different host computers 802 and 806 performing storageoperations with the storage system 500 at substantially the same timeconsistent with some embodiments of the present invention. Herein,docking station [1] 408 is operatively linked with a first mobile RAMdevice 810 and docking station [2] 522 is operatively linked with asecond mobile RAM device 812. Docking station [1] 408 is available forstorage operations at address:sub-address 1:1 404 because thecooperating first mobile RAM device 810 is designated as device [1] 411adapted to store data on media type [1] 411. Docking station [2] 522 isavailable for storage operations at address:sub-address 2:2 514 becausethe cooperating second mobile RAM device 812 is designated as device [2]566 adapted to store data on media type [2] 566. As shown herein, afirst host computer 802 adapted to store data on a storage device type[1] is engaged 804 with docking station [1] 408 for data storageoperations at address 1:1 404. A second host computer 806 adapted tostore data on a storage device type [2] is engaged 808 with dockingstation [2] 522 for data storage operations at address 2:2 514. Dockingstation [3] 524 does not have a cooperating mobile RAM device 114 andhence registers as unavailable for storage operations.

Referring now to FIG. 9, shown therein is a method to practice anembodiment of the present invention. It should be recognized that thesteps presented in the described embodiments of the present invention donot necessarily require any particular sequence. Similar elements areused from FIG. 5A for purposes of illustration in this embodiment. Instep 902, a storage system 500 receives an inquiry from a host computer502. Means for receiving the inquiry can be over a SCSI or fiber channelconnection, for example. In step 904, a first address [1] 409 associatedwith a docking station [1] 408 is provided. The first address [1] 409can be optically transmitted over the same path over which the inquirywas received, for example. In step 906, a first sub-address [0] 403corresponding to a first virtual device, such as a disc drive 414,capable of storing data on a first media, such as a magnetic hard disc,is provided. In addition, a second sub-address [1] 411 corresponding toa second virtual device, such as a tape drive 416, capable of storingdata on a second media, such as a cassette, is also provided. The first[0] 403 and second [1] 411 sub-addresses are associated with the firstaddress [1] 409 in the relationship of address:sub-address as shown byblocks 1:0 402 and 1:1 404 respectively. A means for providing the firstsub-address [0] 403 and second sub-address [1] 411 can be bytransmitting the addresses [0] 403 and [1] 411 associated with address[1] 409 via the same path over which the inquiry was received. In onecommercially used SCSI protocol, both the address and sub-address aretransmitted to the host computer 502 as a 16 byte data package asaddress:sub-address, such as 1:0 402 for example. In step 908, a mobileRAM device 508 is linked with the docking station [1] 408. A means forlinking the mobile RAM device 508 with the docking station [1] 408 couldbe by wire line, wireless, or simply by inserting a mobile RAM deviceinto the docking station [1] 408 whereby electrical connectionselectrically link the docking station [1] 408 and the mobile RAM device508, just to name a few examples. In step 910, the mobile RAM device 508is designated as the first virtual device [0] 403. A means fordesignating the RAM device 508 as the first virtual device [0] 403 canbe accomplished by a switch system, for example, which could furtherinclude a manual switch, an RF driven switch, a programmable switch, ora time based switch (i.e., during day time the mobile RAM device 410 isone device and at night time the mobile RAM device 410 is an alternativedevice), just to name a few examples. A means for designating the RAMdevice 508 can further include an auto switch activated by communicationwith the host computer 502. For example, the mobile RAM device 508 mayconfigure itself as device [0] 403 given an inquiry by the host computer502 is by way of a protocol supporting device [0] 403. In step 912, thehost computer 502 is transmitted a response indicating that the virtualdevice [0] 403 at sub-address [0] 403 is available for storageoperations. A means for responding to the host computer 502 that thefirst virtual device [0] 403 at sub-address [0] 403 is available forstorage operations could by transmitting the information over the samepath that the inquiry was received over. As one skilled in the art willappreciate, other communication and instruction steps may occur betweenthe inquiry step 902 and the responding step 912. In step 914, datareceived from the host computer 502 is stored at the first sub-address[0] 403 which is on the mobile RAM device 508. A means for storing datareceived from the host computer 502 at the first sub-address [0] 403 onthe mobile RAM device 508 can be accomplished by a data conversionprogram capable of converting data received in a protocol by the hostcomputer 502 to data storable on the mobile RAM device 508 such as canbe written by or for an OEM, for example. Another means can beaccomplished by a data conversion processor chip which can be designedby or for an OEM, for example.

FIG. 10 shows an alternative method consistent with some embodiments ofthe present invention and includes method step 902 from FIG. 9. Similarelements are used from FIG. 6 for purposes of illustration in thisembodiment. In step 1002, a first address [1] 409 associated with afirst docking station [1] 408 and a second address [2] 603 associatedwith a second docking station [2] 522 are provided. In step 1004, afirst sub-address [0] 403 corresponding to a first virtual device, suchas a disc drive, capable of storing data on a first media, such as amagnetic hard disc, a second sub-address [1] 411 corresponding to asecond virtual device, such as a tape drive, capable of storing data ona second media, such as a cassette, a third sub-address [0] 562corresponding to a third virtual device, such as a second disc dive,capable of storing data on a third media, such as second disc, and afourth sub-address [1] 564 corresponding to a fourth virtual device,such as second tape drive, capable of storing data on a fourth media,such as second cassette are provided. The first [0] 403 and second [1]411 sub-addresses are associated with the first address [1] 409 and thethird [0] 562 and fourth [1] 564 sub-addresses are associated with thesecond address [2] 603. In step 1006, a first mobile RAM device 602 islinked with the first docking station [1] 408 and a second mobile RAMdevice 604 is linked with the second docking station [2] 522. In step1008, the first mobile RAM device 602 is designated as the first virtualdevice, which is storage device type [0] 506, and the second mobile RAMdevice 604 is designated as the third virtual device, also [0] 506 inthis embodiment. One skilled in the art will appreciate that the thirdvirtual device can be a device different than storage device type [0]506 without departing from the scope and spirit of the invention. Instep 1010, the host computer 502 receives a response that the firstvirtual device [0] 506 at the first sub-address [0] 403 is available forfirst storage operations 620 and that the third virtual device [0] 506at the third sub-address [0] 562 is available for second storageoperations 630. In step 1012, first data is received 620 from the hostcomputer 502 at the first sub-address [0] 403 on the first mobile RAMdevice 602 and second data is received 630 from the host computer 502 atthe third sub-address [0] 562 on the second mobile RAM device 604wherein the second storage operations 630 is capable of occurringsubstantially at the same time as the first storage operations 620.

FIG. 11 shows an alternative method consistent with some embodiments ofthe present invention which includes method steps 1002, 1004, 1006 and1008 from FIG. 10. Similar elements are used from FIG. 8 for purposes ofillustration in this embodiment. In step 1102, storage inquiries arereceived from a first host computer 802 and a second host computer 806.The first host computer 802 is adapted to manage data on a device [1]411 and the second host computer 806 is adapted to manage data on adevice [2] 566. In step 1104, the first host computer 802 receives aresponse that a first virtual device [1] 411 at the first sub-address[1] 411 is available for first storage operations 804 and the secondhost computer 806 receives a response that a third virtual device [2]566 at the third sub-address [2] 566 is available for second storageoperations. In step 1106, data is received 804 from the first host 802(for the first virtual device [1] 411) at the first sub-address [1] 411on the first mobile RAM device 810 and second data is received 808 fromthe second host computer 806 (for the third virtual device [2] 566) atthe third sub-address [2] 566 on the second mobile RAM device 812wherein the second storage operations 808 are capable of occurringsubstantially at the same time as the first storage operations 808.

As shown earlier, embodiments of the present invention can becommercially practiced, for example, with a Spectra Logic RXT Bank ofDrives storage system 200 of FIG. 2, performing as a storage system 106,for use with RXT disc drive magazines 201. The RXT can comprise one ormore RXT docking stations 202 adapted to cooperate with an RXT discdrive magazine 201. As previously described, an RXT disc drive magazine201 encases a plurality of disc drives, such as 308, which can beprovided by Seagate Corporation of Scotts Valley, Calif. As shown inFIG. 12A, a host computer 1201 is capable of initiating commands tocommunicate with the RXT storage system 200. In one exemplaryembodiment, an RXT library 1220 comprises one RXT docking station 1218that is operatively linked with an RXT disc drive magazine 1214 whereinthe RXT disc drive magazine 1216 is designated as a tape device 1216. Inthis embodiment, designation of a tape drive device 1216 is accomplishedwith a manual switch (not shown) disposed on the RXT magazine 201. Thehost computer 1201 will poll the library's 1220 SCSI bus (not shown)searching for devices, in this case the RXT docking station 1218. Thehost computer 1201 will poll the sub-addresses, or LUNs (such as LUN [0]1202), of the address (such as address [5] 1212) corresponding to theone RXT docking station 1218 (in the case of multiple addresses, all theaddresses may be polled for sub-addresses). FIG. 12B shows a dashed oval1230 containing virtual devices 1232, 1240 and 1242 at address [5] 1212associated with the docking station 1218. The virtual devices 1232, 1240and 1242 include a tape device 1232 with a corresponding SCSI address 51204, LUN 0 1202 (5:0) 1206, a disc drive device 5:1 1240 and an opticaldisc device 5:2 1242.

The tape device 1232, disc drive device 1240 and optical disc device1242 are all at the same address [5] 1204, however, each have a uniqueLUN, such as LUN [0] 1202. The host 1201 may either create device filesor may already have device files associated with each of the virtualdevices 1232, 1240 and 1242. When Veritas software, provided by SymantecCorporation of Cupertino, Calif., is used for communication with thedocking station 1218, host level device files are used to “talk” to thedocking station 1218. In one embodiment, the Veritas software will senda SCSI Inquiry command to the virtual drive devices 1232, 1240 and 1242to obtain vendor and product identification. The host computer 1201 willthen send a mode sense command to obtain geometry corresponding to eachvirtual drive device 1232, 1240 and 1242 (as emulated by the dockingstation 1218). Geometry can be the configuration of a virtual systemcorresponding to each virtual drive device 1232, 1240 and 1242. Usingthe geometry information, the Veritas software can issue commands suchas “Read Element Status” to obtain inventory information, such asavailability for storage operations. Upon issuing a “Read ElementStatus”, each virtual drive device 1232, 1240 and 1242 will return allnecessary information for storage operations, such as inventoryinformation, for example. The Veritas software can then “talk” to thetape device 1232 at 5:0 1206, disc drive device 1240 5:1 1206, andoptical disc device 1242 5:2 1210 to obtain individual inventory byusing a “Test Ready Command”. Because the docking station 1218 isoperatively linked with an RXT disc drive magazine 1214 and the RXT discdrive magazine 1218 is designated device [0] 1216 which corresponds tothe virtual tape device 1216, a Test Unit Ready command is returned tothe host computer 1201 indicating that the tape drive 1232 located at5:0 1206 is loaded with a cassette and available to perform storageoperations. The Test Unit Ready command will indicate that the discdrive device 1240 at 5:1 1208 and the optical disc device 1242 at 5:21210 are unavailable for storage operations.

It is to be understood that even though numerous characteristics andadvantages of various embodiments of the present invention have been setforth in the foregoing description, together with the details of thestructure and function of various embodiments of the invention, thisdisclosure is illustrative only, and changes may be made in detail,especially in matters of structure and arrangement of parts within theprinciples of the present invention to the full extent indicated by thebroad general meaning of the terms in which the appended claims areexpressed. For example, as described in FIG. 5A, though communicationbetween a host computer 502 and the docking station [1] 408 generallyconforms with SCSI protocol, the order and initiation of communicationcan vary depending on the protocol used, such as fiber channel forexample, while still maintaining substantially the same functionalitywithout departing from the scope and spirit of the present invention.Further, though communication is described herein as between the hostcomputer 502 and the docking stations, such as docking station [1] 408,communication can be received by the storage system 500 and channeled tothe docking stations without departing from the scope and spirit of thepresent invention. Finally, although the preferred embodiments describedherein are directed to disc drive systems, such as the disc drivemagazine 201, and related technology, it will be appreciated by thoseskilled in the art that the teachings of the present invention can beapplied to other systems, without departing from the spirit and scope ofthe present invention.

It will be clear that the present invention is well adapted to attainthe ends and advantages mentioned as well as those inherent therein.While presently preferred embodiments have been described for purposesof this disclosure, numerous changes may be made which readily suggestthemselves to those skilled in the art and which are encompassed in thespirit of the invention disclosed and as defined in the appended claims.

1. A storage system comprising: at least one mobile random accessstorage device capable of storing first and second data; at least onedocking station associated with an address that is identifiable by atleast one consumer of data; a first sub-address and a second sub-addressassociated with the at least one docking station that are eachidentifiable by the at least one consumer of data; the first sub-addresscorresponding to a first virtual device adapted for storing the firstdata on a first virtual media; the second sub-address corresponding to asecond virtual device adapted for storing the second data on a secondvirtual media wherein the second virtual media is a different media typefrom the first virtual media; and the at least one docking stationadapted to be responsive to the at least one consumer of data as beingavailable for storing the first data at the first sub-address or thesecond data at the second sub-address when the at least one dockingstation is operatively linked with the at least one mobile random accessstorage device.
 2. The storage system of claim 1 wherein the randomaccess storage device is adapted to be designated either the firstvirtual device or the second virtual device.
 3. The storage system ofclaim 2 wherein the at least one docking station is only responsive tothe at least one consumer of data as available for storage at thesub-address corresponding to the designated device.
 4. The storagesystem of claim 2 further comprising a switch system capable ofswitching between the first and the second virtual devices.
 5. Thestorage system of claim 4 wherein the switching system is selected fromthe group consisting of: a manual switch, RF driven switch, programmableswitch, auto switch activated by communication with the consumer ofdata, and time based switch.
 6. The storage system of claim 1 whereinthe at least one mobile random access storage device is selected fromthe group consisting of: flash memory device, magnetic disc drive, discdrive magazine, optical media drive, magneto-optical drive, and floppydisc drive.
 7. The storage system of claim 1 wherein the first virtualdevice is a tape drive and the first media is a tape cassette adapted tocooperate with the tape drive.
 8. The storage system of claim 7 whereina second address associated with the at least one mobile random accessstorage device is a virtual disc drive adapted to be responsive to theat least one consumer of data to record data in a random data format. 9.The storage system of claim 1 wherein the storage system comprises afirst docking station associated with a first address and a seconddocking station associated with a second address and wherein the firstdocking station is adapted to receive the first data for storage on afirst mobile random access storage device and the second docking stationis adapted to receive the second data for storage on a second mobilerandom access storage device from the at least one consumer of data atsubstantially at the same time.
 10. The storage system of claim 1further comprising a third sub-address associated with the dockingstation that is identifiable by the consumer of data; the thirdsub-address corresponding to a third virtual device adapted for storingthird data on a third virtual media wherein the third virtual media is adifferent media type from at least the first virtual media; the dockingstation adapted to be responsive to the at least one consumer of data asavailable for storing the third data at the third sub-address whenoperatively linked with the at least one mobile random access storagedevice.
 11. A method for saving information in a storage systemcomprising: receiving an inquiry from a first consumer of data;providing a first address associated with a first docking station;providing a first sub-address corresponding to a first virtual deviceadapted for storing first data on a first virtual media and a secondsub-address corresponding to a second virtual device adapted for storingsecond data on a second virtual media wherein the second virtual mediais a different media type than the first virtual media and wherein thefirst and second sub-addresses are associated with the first address;operatively linking a first mobile random access storage device with thefirst docking station; designating the first mobile random accessstorage device as the first virtual device; responding to the firstconsumer of data that the first virtual device at the first sub-addressis available for storing first data; storing the first data receivedfrom the first consumer of data at the first sub-address on the firstmobile random access storage device.
 12. The method of claim 11 whereinthe first sub-address in the responding step represents a virtual tapedrive adapted to cooperate with a virtual tape cassette.
 13. The methodof claim 111 wherein the designating step is accomplished with a manualswitch, RF driven switch, programmable switch, auto switch activated bycommunication with the first consumer of data, and time based switch.14. The method of claim 11 further comprising: providing a thirdsub-address corresponding to a third virtual device adapted for storingthird data on a third virtual media wherein the third virtual media is adifferent media type than the first virtual media and wherein the randomaccess storage device is associated with the third sub-address;designating the first mobile access storage device as the third virtualdevice; responding to the first consumer of data that the third virtualdevice at the third sub-address is available for storing the third data;storing the third data received from the first consumer of data at thethird sub-address on the first mobile random access storage device. 15.The method of claim 11 further comprising: providing a second addressassociated with a second docking station; providing a third sub-addresscorresponding to a third virtual device adapted for storing third dataon a third virtual media wherein at least the third virtual media is adifferent media type than the first virtual media and a fourthsub-address corresponding to a fourth virtual device adapted for storingfourth data on a fourth virtual media wherein the third and fourthsub-addresses are associated with the second address; linking a secondmobile random access storage device with the second docking station;designating the second mobile random access storage device as the thirdvirtual device; operatively responding to the first consumer of datathat the third virtual device at the third sub-address is available forstoring third data; storing the third data received from the firstconsumer of data at the third sub-address on the second mobile randomaccess storage device wherein storing the third data is capable ofoccurring substantially at the same time as the first data received fromthe first consumer of data at the first sub-address on the first mobilerandom access storage device.
 16. The method of claim 11 furthercomprising: receiving a second inquiry from a second consumer of data;providing a second address associated with a second docking station;providing a third sub-address corresponding to a third virtual deviceadapted for storing third data on a third virtual media wherein at leastthe third virtual media is a different media type than the first virtualmedia and a fourth sub-address corresponding to a fourth virtual deviceadapted for storing fourth data on a fourth virtual media wherein thethird and fourth sub-addresses are associated with the second address;operatively linking a second mobile random access storage device withthe second docking station; designating the second mobile random accessstorage device as the third virtual device; responding to the secondconsumer of data that the third virtual device at the third sub-addressis available for storing third data; storing the third data receivedfrom the second consumer of data at the third sub-address on the secondmobile random access storage device wherein storing the third data iscapable of occurring substantially at the same time as the first datareceived from the first consumer of data at the first sub-address on thefirst mobile random access storage device.
 17. A system for savinginformation in a storage library comprising: means for receiving aninquiry from a first consumer of data; means for providing a firstaddress associated with a first docking station; means for providing afirst sub-address corresponding to a first virtual device adapted forstoring first data on a first virtual media and a second sub-addresscorresponding to a second virtual device adapted for storing second dataon a second virtual media wherein the second virtual media is adifferent media type than the first virtual media and wherein the firstand second sub-addresses are associated with the first address; meansfor operatively linking a first mobile random access storage device withthe first docking station for operability; means for designating thefirst mobile random access storage device as the first virtual device;means for responding to the first consumer of data that the firstvirtual device at the first sub-address is available for storing firstdata; means for storing the first data received from the first consumerof data at the first sub-address on the first mobile random accessstorage device.
 18. The system of claim 17 further comprising means forswitching the first mobile random access storage device to the secondvirtual device.
 19. The system of claim 17 further comprising: means forproviding a second address associated with a second docking station;means for providing a third sub-address corresponding to a third virtualdevice adapted for storing third data on a third virtual media whereinat least the third virtual media is a different media type than thefirst virtual media and a fourth sub-address corresponding to a fourthvirtual device adapted for storing fourth data on a fourth virtual mediawherein the third and fourth sub-addresses are associated with thesecond address; means for operatively linking a second mobile randomaccess storage device with the second docking station for operability;means for designating the second mobile random access storage device asthe third virtual device; means for responding to the first consumer ofdata that the third virtual device at the third sub-address is availablefor storing third data; means for storing the third data received fromthe first consumer of data at the third sub-address on the second mobilerandom access storage device wherein storing the third data is capableof occurring substantially at the same time as the first data receivedfrom the first consumer of data at the first sub-address on the firstmobile random access storage device.
 20. The system of claim 17 furthercomprising: means for receiving a second inquiry from a second consumerof data; means for providing a second address associated with a seconddocking station; means for providing a third sub-address correspondingto a third virtual device adapted for storing third data on a thirdvirtual media wherein at least the third virtual media is a differentmedia type than the first virtual media and a fourth sub-addresscorresponding to a fourth virtual device adapted for storing fourth dataon a fourth virtual media wherein the third and fourth sub-addresses areassociated with the second address; means for operatively linking asecond mobile random access storage device with the second dockingstation for operability; means for designating the second mobile randomaccess storage device as the third virtual device; means for respondingto the second consumer of data that the third virtual device at thethird sub-address is available for storing third data; means for storingthe third data received from the second consumer of data at the thirdsub-address on the second mobile random access storage device whereinstoring the third data is capable of occurring substantially at the sametime as the first data received from the first consumer of data at thefirst sub-address on the first mobile random access storage device. 21.A storage system comprising: at least one mobile random access storagedevice capable of storing data; at least one docking station adapted toreceive and transmit the data; the at least one mobile random accessstorage device adapted to be designated to function as a first or asecond virtual of storage device wherein the second virtual storagedevice is a different type of device from the first virtual storagedevice; the mobile random access storage device capable of storing thedata intended for storage on the first virtual storage device when theat least one mobile random access storage device is designated as thefirst virtual storage device and the at least one mobile random accessstorage device is operatively linked with the at least one dockingstation.
 22. A storage system comprising: at least one mobile randomaccess storage device capable of storing sequential data and randomdata; at least one docking station; the at least one docking stationassociated with an address wherein the address is identifiable by atleast one consumer of data; a first and second sub-address associatedwith the docking station wherein the first and second sub-addresses areidentifiable by the at least one consumer of data; the first sub-addresscorresponding to a virtual sequential storage device adapted for storingthe sequential data on a virtual sequential storage media; the secondsub-address corresponding to a virtual random storage device adapted forstoring the random data on a virtual random storage media; and the atleast one docking station adapted to be responsive to the at least oneconsumer of data as available for storing the sequential data at thefirst sub-address or the random data at the second sub-address when theat least one docking station is operatively linked with the at least onemobile random access storage device.